• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.05a
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• pp.66-66
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• 2004

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.05a
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• pp.60-60
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• 2004

• Applied Biological Chemistry
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• v.38 no.2
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• pp.123-128
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• 1995

Several factors affecting on transformation efficiency were studied to establish a Agrobacterium rhizogenes mediated system for the transformation of Populus species, and We could obtaine tansgenic plantlets expressing the introduced gene. Leaf sections were more sensitive than stem sections to kanamycin and thought to be better material for transformant screening. The bacterial density did not affect on the efficiency of transformation over the range of $4{\times}10^5{\sim}7{\times}10^9\;cfu$. The optimum period for co-cultivation was one day or shorter. Both of the optimum concentrations of cefotaxime and ampicillin in the medium were $250\;{\mu}g/ml$ for elimination of bacteria from the inoculated leaf sections. The addition of acetosyringone in the bacterial culture medium increased transformation rate, and the highest rate was obtained at $50\;{\mu}M$ of acetosyringone. The transformed galls could be selectively induced and gown on the growth regulator-free medium or on the medium containing $100\;{\mu}g/ml$ or higher contrition of kanamycin. The roots were induced from the galls incited by A. rhizogenes within 3 weeks on the growth regulator-free medium as well as on the medium containing growth regulators. The plantlets were regenerated from the galls cultured for 6 weeks on the medium containing 0.05 mg/ml of NAA and 0.5 mg/ml of BA. The expressions of the introduced opine gene in the transformed galls and plantlets were confirmed by the analysis of agropine and mannopine.

• Journal of Plant Biotechnology
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• v.38 no.4
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• pp.251-257
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• 2011

Rice is the most important crop as a model plant for functional genomics of monocotyledons. Rice is usually transformed using Agrobacterium tumefaciens. However, the transformation efficiency using previous method is still low. In this study, we established a new method by modifying the general Agrobacterium protocol especially in the inoculation and co-cultivation step. We directly inoculated Agrobacterium containing a CIPK15 gene under the control of CaMV 35S promoter and NOS terminator in the pCAM1300 vector into the pre-soaked seeds in N6D media for 24 hours. After 7 days of culture at $25^{\circ}C$, calli were formed on seeds cultured on the co-cultivation medium containing an antioxidant compound (1 mM dithiothreitol) and of Agrobacterium growth-inhibiting agent (3 mg/L silver nitrate). We obtained 35 and 22 transgenic plants in rice cultivars, Gopumbyeo and Ilpumbyeo, with increase of transformation efficiency by 30.4% and 22.6%, respectively compared to the general transformation method. The new method in this study would lead to reduction of substantial labor and time to generate transgenic plants.

• Korean Journal of Plant Tissue Culture
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• v.28 no.5
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• pp.243-248
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• 2001

This study was peformed to find out the optimal conditions for the selection of transformed cells using already established transgenic plants. Several transgenic poplar (Populus alba$\times$P giandulosa) lines carrying npt II or hpt gene as a selectable marker were tested against kanamycin or hygromycin. Two culture explants, leaf discs and nodes, were compared regarding their sensitivity to the antibiotics. When leaf discs of untransformed control plants were cultured on callus inducing media in the presence of varying levels of kanamycin or hygromycin, only those cultured on the media containing lower than 50 mg/L kanamycin or 2 mg/L hygromycin formed callus. However, much higher concentration of kanamycin was needed to suppress the growth of axillary buds of untransformed plants. On the other hand, hygromycin at the concentration of 5 mg/L effectively suppressed shoot growth of untransformed plants. Root induction from untransformed plants could also be suppressed at the concentration of 50 mg/L kanamycin or 5 mg/L hygromycin. The transgenic plants showed resistance to 100 mg/L kanamycin or 50 mg/L hygromycin in the growth of callus, shoots, and roots. Hygromycin appeared to be more efficient in selecting untransformed cells than kanamycin.

• Korean Journal of Plant Resources
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• v.19 no.5
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• pp.634-639
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• 2006

In order to develop a disease-resistant root stock for the growth of watermelon, an efficient regeneration system of the gourd(Lagenaria leucantha Duch.) inbred line GO701-2 via organogenesis was established in this experiment. Using proximal parts of cotyledon explant excised from germinated seedling in vitro, maximum adventitious shoot formation (39%) was achieved on MS medium where cytokinin (BA) and auxin (IAA) were added at a concentration of 3mg/L and 0.1mg/L, respectively. Roots of the elongated shoots were successfully formed on MS medium without adding any plant growth regulators. The cucumber CsGolS1 gene known as a resistance gene against biotic and abiotic stresses, was constructed into the binary vector pBI121 under the control of CaMV 35S promoter. When the gene was introduced into the genome of gourd by Agrobacterium-mediated transformation, putative transgenic plants were obtained with the transformation efficiency of approximately 20 percent.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.13-17
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• 2004

To improve transformation efficiency, the callus of Lilium lancifolium Thunb. were bombarded by particles coated with pIG 121 Hm which include NPT II and GUS genes, and then cocultivated with Agrobacterium tumefaciens EHA101 which contain pIG121Hm binary vector, carrying neomycin phosphotransferase (NPT II) and $\beta$-Glucuronidase (GUS) genes. Three days after cocultivation with Agrobacterium tumefaciens and particle bombardment, the callus clusters were transferred to MS medium containing 1mg/L 2,4-D, 0.1mg/L BAP, 100mg/L kanamycin and 200mg/L carbenicillin. Four weeks after transfer to the selection medium, GUS expression was detected and PCR analysis revealed the presence of NPT II fragment of the expected size (700 bp) in the transformed callus. The GUS expression from Agrobacterium-mediated transformants after particle bombardment increased to over 3-folds compared with that of callus cocultivated with Agrobacterium tumefaciens without particle bombardment. The callus clusters containing kanamycin resistant gene were transferred to MS medium containing 1mg/L NAA and 1mg/L BAP. Somatic embryos were developed in four weeks and microbulbs expressing GUS were formed.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.275-279
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• 2005

Tah tasai chinese cabbage (Brassica campestris var. narinosa), a vegetable plant popularly consumed as several-days-old seedlings in oriental countries, can be easily cultivated using a simple appliance. We demonstrated that Agrobacterium-mediated transformation via vacuum infiltration (agroinfiltration) resulted in a successful transient GUS gene expression in tah tasai chinese cabbage seedlings. Pre-germinated seeds were found to be more susceptible to Agrobacterium infection than one-day-old or two-days-old seedlings. We also demonstrated that hydrogen peroxide (HPO) treatment increased GUS expression especially for two-days-old seedlings. In ELISA using seedlings transformed with hepatitis B surface antigen (HBsAg) DNA by agroinfiltration, HBsAg protein synthesis increased more than two folds by HPO treatment to two-days-old seedlings in comparison to the mock-treated pre-germinated seeds.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.103-108
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• 2003

LinA gene involving in the ${\gamma}$-benzenehexachloride degradation have been cloned from Sphingmonas paucimobilis UT26. This linA gene which catalyzes the first dechlorination step of ${\gamma}$-benzenehexachloride is known to play a key role in the ${\gamma}$-benzenehexachloride degradation pathway in UT26. In this study, the linA gene was designed to clean-up the ${\gamma}$-benzenehexachloride and its derivatives contaminated in soil, water and air using transgenic tobacco plants. The linA transgene was introduced into the chromosome of tobacco using leaf-disk transformation approach as revealed by Southern blot analysis. In addition, mRNA and protein produced by linA gene was expressed at a high level in the leaf tissue as demonstrated by both northern blot analysis and Western bolt analysis with polyclonal antibody against S. paucimobilis UT26. in vitro analysis using GC-MS showed that transgenic tobacco plant produced the linA protein which effectively degraded ${\gamma}$-benzenehexachloride into ${\gamma}$- pentachlorocyclohexene and 1,2,4-trichlobenzene compounds which are less toxic.

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.57-62
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• 2005

Salt-tolerant transgenic Panax ginseng plants were produced by introducing the SAL1 geue (3'(2'), 5'-bis-phosphate nucleotidase) that confers tolerance to the salts through Agrobacterium tumefaciens co-cultivation. Cotyledon explants of immature ginseng zygotic embryos cultured on Murashige and Skoog medium lacking growth regulators formed somatic embryos directly with below 10%, but the 74% tranformation rate were observed at the treatment of phytohormone with 1.0 mg/l 2,4-D and 0.5 mg/l kinetin. Somatic embryos were initially cultured on MS medium supplemented with 250 mg/l cefotaxime for 3 weeks and subsequently subcultured five times to a medium containing 100 mg/l kanamycin and 250 mg/l cefotaxime. Upon development into the cotyledonary stage, these somatic embryos were transferred to on the medium containing 50 mg/l kanamycin and 10 mg/l gibberellic acid to induce germination and strong selection. Integration of the transgene into the plants was confirmed by polymerase chain reaction with specific primers. The ginseng transformants with well-developed shoots and roots were successfully acclimatized in a greenhouse when they were planted in soil.